SocialFolders lets social media mavens move files between their computers and social networks with ease—for the most part. Files sometimes took a long time to sync to social networks—and the ability to upload or download is tied to the target social network you're using—but Facebook, Twitter, and other social network users should check it out.
Free for Dropbox applications. Free for 2GB of space.
Dropbox Pro: $9.99 per month or $99 per year for 1TB of space.
Business: Price varies by number of employees ($15 per month per user, with a minimum of 5 users).